Air cooler



FIG. 1 is a perspective view of an air cooler showing my new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a front elevational view thereof

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The broken lines in the drawings depict portions of the air cooler that form no part of the claimed design. 

CLAIM The ornamental design for an air cooler, as shown and described. 